i currently have a nelsons 91 tune, im gunna order some new long tube headers and get the rear o2's deleated, my question's are 1. how hard and what does it cost to get a retune? 2 i was wondering if it was possable to retune for my low end as well? it boggs down wont even spin a tire in the dirt, like it's running rich whne i go wot from a dig? thanks for the helps guys...